The invention discloses a method for preparing
bismuth ferrite-
barium titanate (BiFeO3-BaTiO3)
ceramic through two-step
sintering, and belongs to the technical field of lead-free
ceramic preparation. The preparation method comprises the following steps: calculating and weighing according to a
chemical formula (1-x) Bi (1 + y) FeO3-xBaTiO3, ball-milling and mixing,
drying, sieving, putting into an
alumina crucible, and pre-
sintering at 780-950 DEG C for 2-12 hours to obtain pre-sintered
powder; carrying out secondary ball milling,
drying at 70-120 DEG C, sieving dried
powder, adding
polyvinyl alcohol with the concentration of 2wt% into the sieved dried
powder, carrying out
grinding granulation, and putting the granulated powder into a mold for
compression molding; placing the
ceramic green body in a
muffle furnace, heating to 300-440 DEG C, discharging glue for 2-4 hours, heating to 950-1060 DEG C, preserving heat for 1-10 minutes, cooling to 900-1060 DEG C,
sintering for 4-12 hours, and cooling to
room temperature along with the furnace to prepare the required ceramic. According to the two-step sintering method disclosed by the invention, by ingeniously controlling the two-step sintering temperature and the heat preservation time, an impure phase generation temperature interval in the
bismuth ferrite-
barium titanate ceramic can be avoided; the prepared ceramic is good in
crystallinity, uniform in component, small in grain size, compact in structure, low in
dielectric loss, high in insulativity, high in remanent polarization intensity and excellent in piezoelectric property and photovoltaic property.